U.S. drug regulators warn that side effects of Ritalin, Daytrana and other similar drugs used to treat Attention Deficit and Hyperactivity Disorder (ADHD) could result in long-lasting and potentially dangerous erections.

In a drug safety communication issued December 17, the FDA indicates drugs that use methylphenidate as an active ingredient, including Daytrana and Ritalin, can cause a condition known as priapism; an erection that lasts a dangerously long time.

Often lampooned in popular culture, priaprism occurs when blood in the penis becomes trapped, leading to prolonged and painful erections. This may also lead to permanent damage to the penis and leaving men with long-lasting consequences.

According to the FDA, data indicates that there are at least 15 known cases of priapism associated with methylphenidate ADHD drugs, with 12 cases reported in patients less than 18 years of age. The FDA warns that boys of this age are less likely to report the problem, due to embarrassment. Two of the patients required surgical intervention, with one ultimately having a shunt implanted and the other requiring needle aspiration.

The FDA warns patients taking the drugs to seek immediate medical care for any erection lasting more than four hours, but also recommends that patients not stop taking the drug without first discussing the situation with their health care professional.

The drug regulatory agency advises doctors to talk to their male patients and caregivers about the risks of priapism from ADHD drugs like Ritalin and Daytrana. The FDA also warns them that another ADHD drug, Strattera, has also been linked to priapism. Four other patients taking ADHD drugs that use amphetamines as active ingredients have suffered the same problem, but they were also taking other drugs at the time, leaving the FDA unable to determine which drug caused the problem.

ADHD Drug Side Effects

The safety warning comes amid growing concerns over the potential side effects of ADHD drugs, which have been increasingly used in recent years as the number of children diagnosed with ADHD has increased.

In January, an analysis of Daytrana adverse event reports received by the FDA found that Daytrana patch problems were reported more often than all other ADHD drugs. Even though the drug only accounts for 3% of sales, Daytrana complaints made up 99% of all ADHD drug adverse events in the second quarter of 2012.

Side effects continue to concern health officials considering the widespread usage of ADHD medications. According to the CDC, as of 2007 5.4 million children ages 4 to 17 were diagnosed with ADHD, widening the risk group with boys being 2.8 times more likely to take medication for ADHD than girls. ADHD drugs are used by 3.3 million American children under the age of 20.